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Differential D14048 Diff 39732 head/sys/netinet/tcp_output.c

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head/sys/netinet/tcp_output.c

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#include <netinet/tcp.h> #include <netinet/tcp.h>
#define TCPOUTFLAGS #define TCPOUTFLAGS
#include <netinet/tcp_fsm.h> #include <netinet/tcp_fsm.h>
#include <netinet/tcp_seq.h> #include <netinet/tcp_seq.h>
#include <netinet/tcp_timer.h> #include <netinet/tcp_timer.h>
#include <netinet/tcp_var.h> #include <netinet/tcp_var.h>
#include <netinet/tcpip.h> #include <netinet/tcpip.h>
#include <netinet/cc/cc.h> #include <netinet/cc/cc.h>
#ifdef TCP_RFC7413
#include <netinet/tcp_fastopen.h> #include <netinet/tcp_fastopen.h>
#endif
#ifdef TCPPCAP #ifdef TCPPCAP
#include <netinet/tcp_pcap.h> #include <netinet/tcp_pcap.h>
#endif #endif
#ifdef TCPDEBUG #ifdef TCPDEBUG
#include <netinet/tcp_debug.h> #include <netinet/tcp_debug.h>
#endif #endif
#ifdef TCP_OFFLOAD #ifdef TCP_OFFLOAD
#include <netinet/tcp_offload.h> #include <netinet/tcp_offload.h>
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#if defined(IPSEC) || defined(IPSEC_SUPPORT) #if defined(IPSEC) || defined(IPSEC_SUPPORT)
unsigned ipsec_optlen = 0; unsigned ipsec_optlen = 0;
#endif #endif
int idle, sendalot; int idle, sendalot;
int sack_rxmit, sack_bytes_rxmt; int sack_rxmit, sack_bytes_rxmt;
struct sackhole *p; struct sackhole *p;
int tso, mtu; int tso, mtu;
struct tcpopt to; struct tcpopt to;
#ifdef TCP_RFC7413
unsigned int wanted_cookie = 0; unsigned int wanted_cookie = 0;
unsigned int dont_sendalot = 0; unsigned int dont_sendalot = 0;
#endif
#if 0 #if 0
int maxburst = TCP_MAXBURST; int maxburst = TCP_MAXBURST;
#endif #endif
#ifdef INET6 #ifdef INET6
struct ip6_hdr *ip6 = NULL; struct ip6_hdr *ip6 = NULL;
int isipv6; int isipv6;
isipv6 = (tp->t_inpcb->inp_vflag & INP_IPV6) != 0; isipv6 = (tp->t_inpcb->inp_vflag & INP_IPV6) != 0;
#endif #endif
INP_WLOCK_ASSERT(tp->t_inpcb); INP_WLOCK_ASSERT(tp->t_inpcb);
#ifdef TCP_OFFLOAD #ifdef TCP_OFFLOAD
if (tp->t_flags & TF_TOE) if (tp->t_flags & TF_TOE)
return (tcp_offload_output(tp)); return (tcp_offload_output(tp));
#endif #endif
#ifdef TCP_RFC7413
/* /*
* For TFO connections in SYN_RECEIVED, only allow the initial * For TFO connections in SYN_RECEIVED, only allow the initial
* SYN|ACK and those sent by the retransmit timer. * SYN|ACK and those sent by the retransmit timer.
*/ */
if (IS_FASTOPEN(tp->t_flags) && if (IS_FASTOPEN(tp->t_flags) &&
(tp->t_state == TCPS_SYN_RECEIVED) && (tp->t_state == TCPS_SYN_RECEIVED) &&
SEQ_GT(tp->snd_max, tp->snd_una) && /* initial SYN|ACK sent */ SEQ_GT(tp->snd_max, tp->snd_una) && /* initial SYN|ACK sent */
(tp->snd_nxt != tp->snd_una)) /* not a retransmit */ (tp->snd_nxt != tp->snd_una)) /* not a retransmit */
return (0); return (0);
#endif
/* /*
* Determine length of data that should be transmitted, * Determine length of data that should be transmitted,
* and flags that will be used. * and flags that will be used.
* If there is some data or critical controls (SYN, RST) * If there is some data or critical controls (SYN, RST)
* to send, then transmit; otherwise, investigate further. * to send, then transmit; otherwise, investigate further.
*/ */
idle = (tp->t_flags & TF_LASTIDLE) || (tp->snd_max == tp->snd_una); idle = (tp->t_flags & TF_LASTIDLE) || (tp->snd_max == tp->snd_una);
if (idle && ticks - tp->t_rcvtime >= tp->t_rxtcur) if (idle && ticks - tp->t_rcvtime >= tp->t_rxtcur)
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/* /*
* Lop off SYN bit if it has already been sent. However, if this * Lop off SYN bit if it has already been sent. However, if this
* is SYN-SENT state and if segment contains data and if we don't * is SYN-SENT state and if segment contains data and if we don't
* know that foreign host supports TAO, suppress sending segment. * know that foreign host supports TAO, suppress sending segment.
*/ */
if ((flags & TH_SYN) && SEQ_GT(tp->snd_nxt, tp->snd_una)) { if ((flags & TH_SYN) && SEQ_GT(tp->snd_nxt, tp->snd_una)) {
if (tp->t_state != TCPS_SYN_RECEIVED) if (tp->t_state != TCPS_SYN_RECEIVED)
flags &= ~TH_SYN; flags &= ~TH_SYN;
#ifdef TCP_RFC7413
/* /*
* When sending additional segments following a TFO SYN|ACK, * When sending additional segments following a TFO SYN|ACK,
* do not include the SYN bit. * do not include the SYN bit.
*/ */
if (IS_FASTOPEN(tp->t_flags) && if (IS_FASTOPEN(tp->t_flags) &&
(tp->t_state == TCPS_SYN_RECEIVED)) (tp->t_state == TCPS_SYN_RECEIVED))
flags &= ~TH_SYN; flags &= ~TH_SYN;
#endif
off--, len++; off--, len++;
} }
/* /*
* Be careful not to send data and/or FIN on SYN segments. * Be careful not to send data and/or FIN on SYN segments.
* This measure is needed to prevent interoperability problems * This measure is needed to prevent interoperability problems
* with not fully conformant TCP implementations. * with not fully conformant TCP implementations.
*/ */
if ((flags & TH_SYN) && (tp->t_flags & TF_NOOPT)) { if ((flags & TH_SYN) && (tp->t_flags & TF_NOOPT)) {
len = 0; len = 0;
flags &= ~TH_FIN; flags &= ~TH_FIN;
} }
#ifdef TCP_RFC7413
/* /*
* On TFO sockets, ensure no data is sent in the following cases: * On TFO sockets, ensure no data is sent in the following cases:
* *
* - When retransmitting SYN|ACK on a passively-created socket * - When retransmitting SYN|ACK on a passively-created socket
* *
* - When retransmitting SYN on an actively created socket * - When retransmitting SYN on an actively created socket
* *
* - When sending a zero-length cookie (cookie request) on an * - When sending a zero-length cookie (cookie request) on an
* actively created socket * actively created socket
* *
* - When the socket is in the CLOSED state (RST is being sent) * - When the socket is in the CLOSED state (RST is being sent)
*/ */
if (IS_FASTOPEN(tp->t_flags) && if (IS_FASTOPEN(tp->t_flags) &&
(((flags & TH_SYN) && (tp->t_rxtshift > 0)) || (((flags & TH_SYN) && (tp->t_rxtshift > 0)) ||
((tp->t_state == TCPS_SYN_SENT) && ((tp->t_state == TCPS_SYN_SENT) &&
(tp->t_tfo_client_cookie_len == 0)) || (tp->t_tfo_client_cookie_len == 0)) ||
(flags & TH_RST))) (flags & TH_RST)))
len = 0; len = 0;
#endif
if (len <= 0) { if (len <= 0) {
/* /*
* If FIN has been sent but not acked, * If FIN has been sent but not acked,
* but we haven't been called to retransmit, * but we haven't been called to retransmit,
* len will be < 0. Otherwise, window shrank * len will be < 0. Otherwise, window shrank
* after we sent into it. If window shrank to 0, * after we sent into it. If window shrank to 0,
* cancel pending retransmit, pull snd_nxt back * cancel pending retransmit, pull snd_nxt back
* to (closed) window, and set the persist timer * to (closed) window, and set the persist timer
▲ Show 20 Lines • Show All 287 Lines • ▼ Show 20 Lines#endif
*/ */
to.to_flags = 0; to.to_flags = 0;
if ((tp->t_flags & TF_NOOPT) == 0) { if ((tp->t_flags & TF_NOOPT) == 0) {
/* Maximum segment size. */ /* Maximum segment size. */
if (flags & TH_SYN) { if (flags & TH_SYN) {
tp->snd_nxt = tp->iss; tp->snd_nxt = tp->iss;
to.to_mss = tcp_mssopt(&tp->t_inpcb->inp_inc); to.to_mss = tcp_mssopt(&tp->t_inpcb->inp_inc);
to.to_flags |= TOF_MSS; to.to_flags |= TOF_MSS;
#ifdef TCP_RFC7413
/* /*
* On SYN or SYN|ACK transmits on TFO connections, * On SYN or SYN|ACK transmits on TFO connections,
* only include the TFO option if it is not a * only include the TFO option if it is not a
* retransmit, as the presence of the TFO option may * retransmit, as the presence of the TFO option may
* have caused the original SYN or SYN|ACK to have * have caused the original SYN or SYN|ACK to have
* been dropped by a middlebox. * been dropped by a middlebox.
*/ */
if (IS_FASTOPEN(tp->t_flags) && if (IS_FASTOPEN(tp->t_flags) &&
Show All 16 Lines if (flags & TH_SYN) {
* send with the SYN than can fit in * send with the SYN than can fit in
* one segment, don't send any more * one segment, don't send any more
* until the SYN|ACK comes back from * until the SYN|ACK comes back from
* the other end. * the other end.
*/ */
dont_sendalot = 1; dont_sendalot = 1;
} }
} }
#endif
} }
/* Window scaling. */ /* Window scaling. */
if ((flags & TH_SYN) && (tp->t_flags & TF_REQ_SCALE)) { if ((flags & TH_SYN) && (tp->t_flags & TF_REQ_SCALE)) {
to.to_wscale = tp->request_r_scale; to.to_wscale = tp->request_r_scale;
to.to_flags |= TOF_SCALE; to.to_flags |= TOF_SCALE;
} }
/* Timestamps. */ /* Timestamps. */
if ((tp->t_flags & TF_RCVD_TSTMP) || if ((tp->t_flags & TF_RCVD_TSTMP) ||
Show All 27 Lines#if defined(IPSEC_SUPPORT) || defined(TCP_SIGNATURE)
* account the size needed to set this TCP option. * account the size needed to set this TCP option.
*/ */
if (tp->t_flags & TF_SIGNATURE) if (tp->t_flags & TF_SIGNATURE)
to.to_flags |= TOF_SIGNATURE; to.to_flags |= TOF_SIGNATURE;
#endif /* TCP_SIGNATURE */ #endif /* TCP_SIGNATURE */
/* Processing the options. */ /* Processing the options. */
hdrlen += optlen = tcp_addoptions(&to, opt); hdrlen += optlen = tcp_addoptions(&to, opt);
#ifdef TCP_RFC7413
/* /*
* If we wanted a TFO option to be added, but it was unable * If we wanted a TFO option to be added, but it was unable
* to fit, ensure no data is sent. * to fit, ensure no data is sent.
*/ */
if (IS_FASTOPEN(tp->t_flags) && wanted_cookie && if (IS_FASTOPEN(tp->t_flags) && wanted_cookie &&
!(to.to_flags & TOF_FASTOPEN)) !(to.to_flags & TOF_FASTOPEN))
len = 0; len = 0;
#endif
} }
/* /*
* Adjust data length if insertion of options will * Adjust data length if insertion of options will
* bump the packet length beyond the t_maxseg length. * bump the packet length beyond the t_maxseg length.
* Clear the FIN bit because we cut off the tail of * Clear the FIN bit because we cut off the tail of
* the segment. * the segment.
*/ */
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* last segment. * last segment.
*/ */
if (tp->t_flags & TF_NEEDFIN) if (tp->t_flags & TF_NEEDFIN)
sendalot = 1; sendalot = 1;
} else { } else {
len = tp->t_maxseg - optlen - ipoptlen; len = tp->t_maxseg - optlen - ipoptlen;
sendalot = 1; sendalot = 1;
#ifdef TCP_RFC7413
if (dont_sendalot) if (dont_sendalot)
sendalot = 0; sendalot = 0;
#endif
} }
} else } else
tso = 0; tso = 0;
KASSERT(len + hdrlen + ipoptlen <= IP_MAXPACKET, KASSERT(len + hdrlen + ipoptlen <= IP_MAXPACKET,
("%s: len > IP_MAXPACKET", __func__)); ("%s: len > IP_MAXPACKET", __func__));
/*#ifdef DIAGNOSTIC*/ /*#ifdef DIAGNOSTIC*/
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bcopy((u_char *)&sack_seq, optp, sizeof(sack_seq)); bcopy((u_char *)&sack_seq, optp, sizeof(sack_seq));
optp += sizeof(sack_seq); optp += sizeof(sack_seq);
optlen += TCPOLEN_SACK; optlen += TCPOLEN_SACK;
sack++; sack++;
} }
TCPSTAT_INC(tcps_sack_send_blocks); TCPSTAT_INC(tcps_sack_send_blocks);
break; break;
} }
#ifdef TCP_RFC7413
case TOF_FASTOPEN: case TOF_FASTOPEN:
{ {
int total_len; int total_len;
/* XXX is there any point to aligning this option? */ /* XXX is there any point to aligning this option? */
total_len = TCPOLEN_FAST_OPEN_EMPTY + to->to_tfo_len; total_len = TCPOLEN_FAST_OPEN_EMPTY + to->to_tfo_len;
if (TCP_MAXOLEN - optlen < total_len) { if (TCP_MAXOLEN - optlen < total_len) {
to->to_flags &= ~TOF_FASTOPEN; to->to_flags &= ~TOF_FASTOPEN;
continue; continue;
} }
*optp++ = TCPOPT_FAST_OPEN; *optp++ = TCPOPT_FAST_OPEN;
*optp++ = total_len; *optp++ = total_len;
if (to->to_tfo_len > 0) { if (to->to_tfo_len > 0) {
bcopy(to->to_tfo_cookie, optp, to->to_tfo_len); bcopy(to->to_tfo_cookie, optp, to->to_tfo_len);
optp += to->to_tfo_len; optp += to->to_tfo_len;
} }
optlen += total_len; optlen += total_len;
break; break;
} }
#endif
default: default:
panic("%s: unknown TCP option type", __func__); panic("%s: unknown TCP option type", __func__);
break; break;
} }
} }
/* Terminate and pad TCP options to a 4 byte boundary. */ /* Terminate and pad TCP options to a 4 byte boundary. */
if (optlen % 4) { if (optlen % 4) {
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